1. [Technical Field]
The present invention relates to a method of manufacturing a light-emitting device which includes a light-emitting source such as a light emitting diode (LED) chip and to an apparatus for manufacturing such a light-emitting device.
2. [Background Art]
Conventionally, research and development has been conducted in various places on a light-emitting device which includes a LED chip that is a light-emitting source, and fluorescent particles as wavelength conversion materials (e.g., fluorescent pigment, and fluorescent dye) that are excited by light emitted from the LED chip and emit light different in color from the LED chip (for example, see Japanese Unexamined Patent Application Publication No. 2007-35951).
As such a light-emitting device, for example, a white light-emitting device (generally referred to as a white LED) which emits white light by combining a LED chip, which emits blue light or ultraviolet light, and fluorescent particles, which emit yellow light by converting a wavelength of blue light or a similar type of light, is commercially available.
Japanese Unexamined Patent Application Publication No. 2007-35951 describes, as shown in FIG. 9, an example of such a light-emitting device which includes: a LED chip 100, a mounting board 101 on which the LED chip 100 is mounted; a translucent sealing portion 102 which is in a semispherical shape and seals, on a mounting surface of the mounting board 101, the LED chip 100; a dome-shaped sealing member 103 which is formed to cover the translucent sealing portion 102 and fixed to the mounting board 101; and an air layer 104 formed between the translucent sealing portion 102 and the dome-shaped sealing member 103. The translucent sealing portion 102 includes fluorescent particles. The light-emitting device provides white light by using, as the LED chip 100, a GaN-based ultra-violet LED chip which emits ultraviolet light, and, as the fluorescent particles, red fluorescent particles, green fluorescent particles, and blue fluorescent particles.
Applying the light-emitting device shown in FIG. 9, a light-emitting device which provides white light by using, as the LED chip 100, a blue LED chip which emits blue light, and, as the fluorescent particles, yellow fluorescent particles is also conceivable.
The above-described light-emitting device is manufactured by applying, onto the LED chip 100, resin including fluorescent particles so that the fluorescent resin forms the translucent sealing portion 102.
When manufacturing the light-emitting device, there is a case where chromaticity of light emitted by the light-emitting device (hereinafter simply referred to as “chromaticity of light-emitting device”) is not constant, which causes variation in the chromaticity of the manufactured light-emitting device. In view of this, as a light-emitting manufacturing apparatus which prevents occurrence of variation to chromaticity of the manufactured light-emitting device, a conventional manufacturing apparatus 105 shown in FIG. 10 is described in Japanese Unexamined Patent Application Publication No. 2004-516925.
The conventional manufacturing apparatus 105 includes: a syringe 106 which is for storing resin (fluorescent resin) including fluorescent particles; an air dispenser 107 which is for applying, onto the LED chip 100, fluorescent resin discharged from the syringe 106; a weight measurement unit 108 which measures a weight of the fluorescent resin discharged from the air dispenser 107; and a control unit 109 which causes the air dispenser 107 to discharge the fluorescent resin at a constant weight based on the value measured by the weight measuring unit 108.
The conventional manufacturing apparatus 105 employs, in order to manufacture a light-emitting device of constant chromaticity, a technique which allows the air dispenser 107 to discharge the fluorescent resin at a constant weight. It should be noted that chromaticity indicates chromaticity coordinates of the chromaticity diagram established by CIE (Commission Internationale de I'Eclairage).